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先来几张实现图

任务管理页.

新建任务管理.目前实现叫简单的需求...若各位同学要实现复杂的设计...quartz都有提供强大的支持.小弟目前的需求做到这已经够用了.

接下来.我们如何实现quartz的热部署编码呢?

小弟是利用spring整合quzrtz实现的.但是会产生两个小问题.

我们先看看quartz如何与spring整合

<bean name="quartzScheduler" class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="applicationContextSchedulerContextKey" value="applicationContextKey"/>
<property name="configLocation" value="classpath:quartz.properties"/><!--
这个是必须的,QuartzScheduler 延时启动,应用启动完后 QuartzScheduler 再启动
-->
<property name="startupDelay" value="30"/><!--
这个是可选,QuartzScheduler 启动时更新己存在的Job,这样就不用每次修改targetObject后删除qrtz_job_details表对应记录了
-->
<property name="overwriteExistingJobs" value="true"/>
<property name="jobDetails" >
<list>
<ref bean="xxxJobDetail"/>

</list>
</property>
</bean>

首先.我们需要添加一个数据源给quzrtz.允许其序列化JobDetail到数据库.之后有注释.呵呵.我就不必多说了.

<bean id="xxxJobDetail" class="frameworkx.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
<!--shouldRecover属性为true,则当Quartz服务被中止后,再次启动任务时会尝试恢复执行之前未完成的所有任务-->
<!--<property name="shouldRecover" value="true"/>-->
<!-- 标识job是持久的,删除触发器的时候不被删除 -->
<property name="durable" value="true"/>
<property name="targetObject" ref="xxxxJob"/>
  
<!-- 此处是需要执行的任务的方法 -->
<property name="targetMethod" value="executeJob"/>
</bean>

凡是使用过quartz跟spring整合的同学会发现.为什么class的命名空间不是org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean呢?

因为spring技术小组的class会报NotSerializableException.且功能不强shouldRecover,durable这些基础属性不提供...大概spring的MethodInvokingJobDetailFactoryBean根本不支持JobDetail的序列化...想详细了解原因.可以看spring的源码.目前小弟使用的spring3,spring小组依然没解决这问题,应该说还不支持JobDetail序列化.但国外牛人们已经帮我们解决好了.详细见下连接

http://jira.springframework.org/browse/SPR-3797

好了.接下来我们需要配置quzrtz的properties(放到classpath下.quzrtz就能找到)

org.quartz.scheduler.instanceName = DefaultQuartzScheduler
org.quartz.scheduler.rmi.export
= false
org.quartz.scheduler.rmi.proxy
= false
org.quartz.scheduler.wrapJobExecutionInUserTransaction
= false

org.quartz.threadPool.
class = org.quartz.simpl.SimpleThreadPool
org.quartz.threadPool.threadCount
= 10
org.quartz.threadPool.threadPriority
= 5
org.quartz.threadPool.threadsInheritContextClassLoaderOfInitializingThread
= true

org.quartz.jobStore.misfireThreshold
= 60000

#org.quartz.jobStore.
class = org.quartz.simpl.RAMJobStore

org.quartz.jobStore.
class = org.quartz.impl.jdbcjobstore.JobStoreTX
#org.quartz.jobStore.driverDelegateClass
=org.quartz.impl.jdbcjobstore.HSQLDBDelegate
org.quartz.jobStore.driverDelegateClass
=org.quartz.impl.jdbcjobstore.StdJDBCDelegate
#org.quartz.jobStore.useProperties
= true
org.quartz.jobStore.tablePrefix
= QRTZ_
org.quartz.jobStore.isClustered
= false
org.quartz.jobStore.maxMisfiresToHandleAtATime
=1

我们这次是选择org.quartz.jobStore.class = org.quartz.impl.jdbcjobstore.JobStoreTX

而不是默认的org.quartz.jobStore.class = org.quartz.simpl.RAMJobStore简单存储在内存中.

接来下,我们需要一个quartz的scheduler管理类.

protected final Log log = LogFactory.getLog(getClass());
private Scheduler scheduler;
private QuartzDao quartzDao;

private static final Logger logger = LoggerFactory.getLogger(SchedulerServiceImpl.class);



public void setScheduler(Scheduler scheduler) {
this.scheduler = scheduler;
}


public void setQuartzDao(QuartzDao quartzDao) {
this.quartzDao = quartzDao;
}

/**
* 根据job的名称获取job,进而添加到trigger
*
@param name
*
@param jobName
*
@param cronExpression
*
@param group
*
@throws SchedulerException
*/

public void schedule(String name, String jobName, String cronExpression,String group) throws SchedulerException {
if (name == null || name.trim().equals("")) {
name
= UUID.randomUUID().toString();
}

try {
JobDetail jobDetail
= scheduler.getJobDetail(jobName, group);

if(jobDetail != null) {
scheduler.addJob(jobDetail,
true);

CronTrigger cronTrigger
= new CronTrigger(name, group, jobDetail.getName(),
Scheduler.DEFAULT_GROUP);
cronTrigger.setCronExpression(
new CronExpression(cronExpression));
scheduler.scheduleJob(cronTrigger);
scheduler.rescheduleJob(cronTrigger.getName(), cronTrigger.getGroup(), cronTrigger);
}
else
log.error(
"无法找到对应的job.所以无法建立trigger");


}
catch (SchedulerException e) {
log.error(e.getMessage());
throw new SchedulerException();
}
catch (ParseException e) {
log.error(e.getMessage());
}
}

public List<Map<String, Object>> getQrtzTriggers(){
return quartzDao.getQrtzTriggers();
}


public void pauseTrigger(String triggerName,String group) throws SchedulerException{
try {
scheduler.pauseTrigger(triggerName, group);
//停止触发器
} catch (SchedulerException e) {
log.error(e.getMessage());
throw new SchedulerException();
}
}


public void resumeTrigger(String triggerName,String group) throws SchedulerException{
try {
scheduler.resumeTrigger(triggerName, group);
//重启触发器
} catch (SchedulerException e) {
log.error(e.getMessage());
throw new SchedulerException();
}
}


public boolean removeTrigdger(String triggerName,String group) throws SchedulerException{
try {

scheduler.pauseTrigger(triggerName, group);
//停止触发器
return scheduler.unscheduleJob(triggerName, group);//移除触发器
} catch (SchedulerException e) {
log.error(e.getMessage());
throw new SchedulerException();
}
}


public String[] getJobNames(String group) throws SchedulerException {
String[] jobNames
= null;
try {
jobNames
= scheduler.getJobNames(group);
}
catch (SchedulerException e) {
log.error(e.getMessage());
throw new SchedulerException();
}
return jobNames;
}

但前只是简单实现通过cornexpression.若有复杂配置trigger规则的.或需要对trigger添加calendar...可以自己进行扩展.

一下是quzrtzDao的实现

private DataSource dataSource;

public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}

public List<Map<String, Object>> getQrtzTriggers() {
List
<Map<String, Object>> results = getJdbcTemplate().queryForList("select * from QRTZ_TRIGGERS order by start_time");
long val = 0;
String temp
= null;
for (Map<String, Object> map : results) {
temp
= MapUtils.getString(map, "trigger_name");
if(StringUtils.indexOf(temp, "#") != -1){
map.put(
"display_name", StringUtils.substringBefore(temp, "#"));
}
else{
map.put(
"display_name", temp);
}

val
= MapUtils.getLongValue(map, "next_fire_time");
if (val > 0) {
map.put(
"next_fire_time", DateFormatUtils.format(val, "yyyy-MM-dd HH:mm:ss"));
}

val
= MapUtils.getLongValue(map, "prev_fire_time");
if (val > 0) {
map.put(
"prev_fire_time", DateFormatUtils.format(val, "yyyy-MM-dd HH:mm:ss"));
}

val
= MapUtils.getLongValue(map, "start_time");
if (val > 0) {
map.put(
"start_time", DateFormatUtils.format(val, "yyyy-MM-dd HH:mm:ss"));
}

val
= MapUtils.getLongValue(map, "end_time");
if (val > 0) {
map.put(
"end_time", DateFormatUtils.format(val, "yyyy-MM-dd HH:mm:ss"));
}

map.put(
"statu",status.get(MapUtils.getString(map, "trigger_state")));
}

return results;
}


public static final Map<String,String> status = new HashMap<String,String>();


static{
status.put(
"ACQUIRED", "运行");
status.put(
"PAUSED", "暂停");
status.put(
"WAITING", "等待");

}

private JdbcTemplate getJdbcTemplate() {
return new JdbcTemplate(this.dataSource);
}

同学们可以根据自己的风格,修改一下其代码.

此时我们就可以创建一个简单的quzrtz的热部署管理.

我之前讲过会有两个问题.第二个问题是什么呢?还记得讲过我们需要讲jobDetail序列化到数据库吗?因为我们使用了spring 系统中的manager类通过spring的IOC依赖注入.那我们的跟quartz相关的manager都需要声明实现Serializable序列化接口.

此时我们可以想到用ContextLoader.getCurrentWebApplicationContext()把相应的manage通过bean id get出来.

public class SpringBeanProvide implements Serializable/*, ApplicationContextAware*/{


/**
*
*/
private static final long serialVersionUID = 8430477279431126488L;
private ApplicationContext context;

@SuppressWarnings(
"unchecked")
public <T> T getBean(Class<T> clazz, String beanName){
context
= ContextLoader.getCurrentWebApplicationContext();
return (T)context.getBean(beanName);
}

public ServletContext getServletContext() {
WebApplicationContext webContext
= ContextLoader.getCurrentWebApplicationContext();
return webContext.getServletContext();
}

/*@Autowired
public void setApplicationContext(ApplicationContext context)
throws BeansException {
this.context = context;

}
*/
}

我们看看ContextLoader.getCurrentWebApplicationContext()的源码

/**
* Obtain the Spring root web application context for the current thread
* (i.e. for the current thread's context ClassLoader, which needs to be
* the web application's ClassLoader).
*
@return the current root web application context, or <code>null</code>
* if none found
*
@see org.springframework.web.context.support.SpringBeanAutowiringSupport
*/
public static WebApplicationContext getCurrentWebApplicationContext() {
ClassLoader ccl
= Thread.currentThread().getContextClassLoader();
if (ccl != null) {
WebApplicationContext ccpt
= currentContextPerThread.get(ccl);
if (ccpt != null) {
return ccpt;
}
}
return currentContext;
}

currentContextPerThread是一个final的ConcurrentHashMap.也是IOC容器存储bean的一个hash表.

到底什么时候才把ccl设置到currentContextPerThread中呢?

我们往上看源码

try {
// Determine parent for root web application context, if any.
ApplicationContext parent = loadParentContext(servletContext);

// Store context in local instance variable, to guarantee that
// it is available on ServletContext shutdown.
this.context = createWebApplicationContext(servletContext, parent);
servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE,
this.context);

ClassLoader ccl
= Thread.currentThread().getContextClassLoader();
if (ccl == ContextLoader.class.getClassLoader()) {
currentContext
= this.context;
}
else if (ccl != null) {
currentContextPerThread.put(ccl,
this.context);
}
其中...currentContextPerThread.put(ccl, this.context);是在ApplicationContext parent = loadParentContext(servletContext);之下.

ContextLoader.getCurrentWebApplicationContext()只能在容器完全初始化后才能使用..这对于单元测试时...ccpt返回出来的是一个null...

这就是我为什么会在SpringBeanProvide出现注释了ApplicationContextAware的原因...因为本人有点懒...哈哈..没重新整理一份spring的bean xml作为单元测试使用...所以...在单元测试时...改一下注释...就去跑了..呵呵...此时...我们已经可以使用quzrtz的热部署.不必重启服务器就可以对任务进行管理了.

以上的实现.参考了javaeye中的部分文章.

posted on 2011-04-04 13:19 pigwing 阅读(...) 评论(...) 编辑 收藏